Added a11y alert on entering overview mode

chrome/browser/ui/ash/chrome_shell_delegate_chromeos.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/ash/chrome_shell_delegate.h"
 
 #include "ash/accelerators/magnifier_key_scroller.h"
 #include "ash/accelerators/spoken_feedback_toggler.h"
 #include "ash/accessibility_delegate.h"
 #include "ash/media_delegate.h"
@@ skipping 165 matching lines @@
     Profile* profile = ProfileManager::GetActiveUserProfile();
     if (profile) {
       switch (alert) {
         case ash::A11Y_ALERT_WINDOW_NEEDED: {
           AccessibilityAlertInfo event(
               profile, l10n_util::GetStringUTF8(IDS_A11Y_ALERT_WINDOW_NEEDED));
           SendControlAccessibilityNotification(
               ui::AX_EVENT_ALERT, &event);
           break;
         }
+        case ash::A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED: {
+          AccessibilityAlertInfo event(
+              profile, l10n_util::GetStringUTF8(
+                  IDS_A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED));
+          SendControlAccessibilityNotification(
+              ui::AX_EVENT_ALERT, &event);
+          break;
+        }
         case ash::A11Y_ALERT_NONE:
           break;
       }
     }
   }
 
   virtual ash::AccessibilityAlert GetLastAccessibilityAlert() OVERRIDE {
     return ash::A11Y_ALERT_NONE;
   }
 
@@ skipping 100 matching lines @@
 }
 
 void ChromeShellDelegate::PlatformInit() {
   registrar_.Add(this,
                  chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_SESSION_STARTED,
                  content::NotificationService::AllSources());
 }